Systems and methods for measuring tissue impedance through an electrosurgical cable

Abstract

The electrosurgical systems and methods of the present disclosure include a tissue resistance measurement system that compensates for capacitive parasitics in a cable connecting an electrosurgical generator to and electrosurgical cable to estimate the real resistance of a tissue load. The electrosurgical generator includes an output stage coupled to an electrical energy source and generates electrosurgical energy. The electrosurgical generator includes a plurality of sensors sensing a voltage and current of the electrosurgical energy and a controller controlling the output stage. The controller includes a calculator that calculates a real part of an impedance based on the sensed voltage and current, an estimator that estimates a resistance of the tissue using a solution to a quadratic equation that is a function of the real part of the impedance, and a control signal generator configured to generate a control signal for the output stage based on the resistance of the tissue.

Description

CROSS REFERENCE TO RELATED APPLICATION[0001]The present application claims the benefit of and priority to U.S. Provisional Application Ser. No. 61 / 859,601, filed on Jul. 29, 2013, the entire contents of which are incorporated herein by reference.BACKGROUND[0002]1. Technical Field[0003]The present disclosure relates to electrosurgery. More particularly, the present disclosure relates to electrosurgical systems and methods for measuring tissue impedance through an electrosurgical cable.[0004]2. Background of Related Art[0005]Electrosurgery involves the application of high-frequency electric current to cut or modify biological tissue during an electrosurgical procedure. Electrosurgery is performed using an electrosurgical generator, an active electrode, and a return electrode. The electrosurgical generator (also referred to as a power supply or waveform generator) generates an alternating current (AC), which is applied to a patient's tissue through the active electrode and is returned ...

AI Technical Summary

Benefits of technology

The patent text is about a new way to measure power and tissue resistance in electrosurgical systems. This method uses filters to accurately measure these things, which reduces the amount of memory and processing power needed. The technical effect is improved accuracy in measuring power and tissue resistance.

Problems solved by technology

Although many other variables affect the total heating of the tissue, increased current density usually leads to increased heating.

The cable creates a circuit network between the voltage and current sensors and the tissue being treated, which results in inaccurate power and impedance measurements.

However, solutions to these equations, when implemented by a real-time embedded software system, may require a significant amount of memory and processing power.

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